lkml.org 
[lkml]   [2017]   [Oct]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [tip:x86/mm] x86/mm: Add support for early encryption/decryption of memory
From
Date
On 10/25/2017 12:34 PM, Dave Hansen wrote:
> On 07/18/2017 03:51 AM, tip-bot for Tom Lendacky wrote:
>> +/*
>> + * This routine does not change the underlying encryption setting of the
>> + * page(s) that map this memory. It assumes that eventually the memory is
>> + * meant to be accessed as either encrypted or decrypted but the contents
>> + * are currently not in the desired state.
>> + *
>> + * This routine follows the steps outlined in the AMD64 Architecture
>> + * Programmer's Manual Volume 2, Section 7.10.8 Encrypt-in-Place.
>> + */
>> +static void __init __sme_early_enc_dec(resource_size_t paddr,
>> + unsigned long size, bool enc)
>> +{
>> + void *src, *dst;
>> + size_t len;
>> +
>> + if (!sme_me_mask)
>> + return;
>> +
>> + local_flush_tlb();
>> + wbinvd();
>
> What is this TLB flush for? WBINVD is mentioned in "Volume 2, Section
> 7.10.8", but TLB flushes are not. Is it OK that this does not flush
> global pages?

The local_flush_tlb() is not needed and can be removed. I had that in
there from early development and testing and just missed removing it.
I can queue up a patch to delete it and remove the ambiguity with this
routine and the APM document.

Thanks,
Tom

>

\
 
 \ /
  Last update: 2017-10-26 15:06    [W:0.126 / U:0.264 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site